U.S. patent application number 11/681972 was filed with the patent office on 2007-09-13 for photovoltaic module mounting clip with integral grounding.
This patent application is currently assigned to PowerLight Corporation. Invention is credited to Carl J. Lenox.
Application Number | 20070212935 11/681972 |
Document ID | / |
Family ID | 38475777 |
Filed Date | 2007-09-13 |
United States Patent
Application |
20070212935 |
Kind Code |
A1 |
Lenox; Carl J. |
September 13, 2007 |
Photovoltaic Module Mounting Clip with Integral Grounding
Abstract
An electrically conductive mounting/grounding clip, for use with
a PV assembly of the type having an electrically conductive frame,
comprises an electrically conductive body. The body has a central
portion and first and second spaced-apart arms extending generally
perpendicular to the central portion. Each arm has an outer portion
with each outer portion having an outer end. At least one frame
surface-disrupting element is at each outer end. The central
portion defines a plane with the frame surface-disrupting elements
pointing towards the plane. In some examples each arm extends from
the central portion at an acute angle to the plane.
Inventors: |
Lenox; Carl J.; (Oakland,
CA) |
Correspondence
Address: |
HAYNES BEFFEL & WOLFELD LLP
P O BOX 366
HALF MOON BAY
CA
94019
US
|
Assignee: |
PowerLight Corporation
Berkeley
CA
|
Family ID: |
38475777 |
Appl. No.: |
11/681972 |
Filed: |
March 5, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60780819 |
Mar 9, 2006 |
|
|
|
60821869 |
Aug 9, 2006 |
|
|
|
Current U.S.
Class: |
439/567 |
Current CPC
Class: |
H02S 20/23 20141201;
F24S 25/636 20180501; Y02B 10/10 20130101; F24S 25/61 20180501;
Y02E 10/47 20130101; F24S 25/634 20180501; F24S 2025/021 20180501;
Y10T 24/44 20150115; F24S 2025/6008 20180501; H01R 4/64 20130101;
Y02E 10/50 20130101; F24S 25/20 20180501 |
Class at
Publication: |
439/567 |
International
Class: |
H01R 13/60 20060101
H01R013/60 |
Claims
1. An electrically conductive mounting/grounding clip for use with
PV assemblies of the type having electrically conductive frames
separated by gaps, the clip comprising: an electrically conductive
body comprising a central portion and first and second spaced-apart
arms extending generally perpendicular to the central portion; each
arm having an outer portion, each outer portion having first and
second outer ends; a frame surface-disrupting element at each outer
end; the central portion defining a plane; and the frame
surface-disrupting elements pointing towards the plane.
2. The clip according to claim 1 wherein the frame
surface-disrupting elements comprise frame-surface-penetrating
teeth.
3. The clip according to claim 1 wherein the arms are generally
T-shaped.
4. The clip according to claim 1 wherein each arm extends from the
central portion at an acute angle to the plane.
5. The clip according to claim 4 wherein the acute angle is
80-88.degree..
6. The clip according to claim 4 wherein the acute angle is about
83.degree..
7. The clip according to claim 1 further comprising a plurality of
said frame surface-disrupting elements at each outer end.
8. The clip according to claim 7 wherein the frame
surface-disrupting elements of each arm are oriented in a direction
generally parallel to a line connecting the outer ends of said
arm.
9. An electrically conductive mounting/grounding clip for use with
PV assemblies of the type having electrically conductive frames
separated by gaps, the clip comprising: an electrically conductive
body comprising a central portion and first and second
spaced-apart, generally T-shaped arms extending from the central
portion; each arm extending from the central portion at an acute
angle to the plane; each arm having an outer portion, each outer
portion having first and second outer ends; a plurality of frame
surface-disrupting elements at each outer end; the frame
surface-disrupting elements of each arm being oriented in a
direction generally parallel to a line connecting the outer ends of
said arm; and the central portion defining a plane and the frame
surface-disrupting elements pointing towards the plane.
10. An electrically conductive mounting/grounding clip assembly for
use with PV assemblies of the type having electrically conductive
frames separated by gaps, the clip assembly comprising: an
electrically conductive clip comprising: a central portion and
first and second spaced-apart arms extending generally
perpendicular to the central portion; each arm having an outer
portion, each outer portion having first and second outer ends; a
frame surface-disrupting element at each outer end; and the central
portion defining a plane and the frame surface-disrupting elements
pointing towards the plane; a second member; and means for (1)
biasing the frame surface-disrupting elements of the clip against
electrically conductive frames of adjacent PV assemblies thereby
electrically connecting the frames to one another through the clip,
and (2) securing the clip to the second member.
11. A PV installation comprising: a support; first and second PV
assemblies of the type having electrically conductive frames
separated by a gap, the frames each having an upper surface; and an
electrically conductive mounting/grounding clip assembly for use
with the first and second PV assemblies, the clip assembly
comprising: an electrically conductive clip comprising: a central
portion and first and second spaced-apart, generally T-shaped arms
extending generally perpendicular to the central portion, the
central portion and arms defining an access region accessible from
above; each arm having an outer portion, each outer portion having
first and second outer ends; at least one frame surface-disrupting
element at each outer end; and the central portion defining a
plane; a second member positioned generally beneath the first and
second PV assemblies and supported by the support; an elongated
connection member securing the clip to the second member and
extendable within the gap between the electrically conductive
frames so that the frame-disrupting element can be forced against
the electrically conductive frames thereby electrically connecting
the frames to one another through the clip; and the central portion
comprising a hole and the elongated connection member comprising a
connection element passing through the hole, the connection element
having an upper end, the upper end located completely within the
access region and below the upper surface.
12. The PV installation according to claim 11 wherein the frame
surface-disrupting elements point towards the plane.
13. The PV installation according to claim 11 wherein each arm
extends from the central portion at an acute angle to the
plane.
14. The clip assembly according to claim 11 further comprising a
plurality of said frame surface-disrupting elements at each outer
end.
15. The PV installation according to claim 11 further comprising a
plurality of the frame surface-disrupting elements at each outer
end, the frame surface-disrupting elements of each arm oriented in
a direction generally perpendicular to the frames.
16. The PV installation according to claim 11 wherein connection
element comprises a bolt, the upper end comprises a bolt head, and
the second member comprises a threaded hole with which the bolt is
threadably engaged.
17. The PV installation according to claim 11 wherein connection
element comprises a stud extending from the second member and the
upper end comprises a threaded portion of the stud and a nut
threadably engaging the threaded portion.
18. The PV installation according to claim 11 wherein the support
comprises a chosen one of a building roof, a support frame member
and the ground.
19. The PV installation according to claim 11 wherein the frame
comprises an electrically non-conductive surface and the frame
surface-disrupting portion comprises surface-penetrating teeth.
20. The PV installation according to claim 11 wherein the clip
assembly further comprises means for preventing the clip from
tipping away from the frame as the clip is biased against the frame
by the elongated connection member.
21. The PV installation according to claim 11 further comprising
spacer means for properly spacing the first and second PV
assemblies so that said gap is a properly sized gap to accommodate
thermal expansion and contraction.
22. An electrically conductive mounting/grounding clip for use with
a PV assembly of the type having an electrically conductive frame,
the clip comprising: an electrically conductive body comprising a
central portion and first and second spaced-apart arms extending
generally perpendicular to the central portion; each arm having an
outer portion, each outer portion having an outer end; a plurality
of frame surface-disrupting elements at each outer end; and the
central portion defining a plane with the frame surface-disrupting
elements pointing towards the plane.
23. The clip according to claim 22 wherein each arm extends from
the central portion at an acute angle to the plane.
24. An electrically conductive mounting/grounding clip assembly for
use with a PV assembly of the type having electrically conductive
frame, the clip assembly comprising: an electrically conductive
clip comprising: a central portion and first and second
spaced-apart arms extending from the central portion; each arm
having an outer portion, each outer portion having an outer end; a
frame surface-disrupting element at each outer end; and the central
portion defining a plane and the frame surface-disrupting elements
pointing towards the plane; a second member supportable by a
support element; means for (1) biasing the frame surface-disrupting
elements of the clip against the electrically conductive frame of
an adjacent PV assembly thereby electrically connecting the frame
to the clip, and (2) securing the clip to the second member; means
for preventing the clip from tipping away from the frame as the
clip is biased against the frame by the biasing and securing
means.
25. The clip assembly according to claim 23 wherein each arm
extends from the central portion at an acute angle to the
plane.
26. A PV installation comprising: a support; a PV assembly of the
type having an electrically conductive frame, the frame having an
upper surface; and an electrically conductive mounting/grounding
clip assembly for use with the PV assembly, the clip assembly
comprising: an electrically conductive clip comprising: a central
portion and first and second spaced-apart arms extending generally
perpendicular to the central portion, the central portion and arms
defining an access region accessible from above; each arm having an
outer portion, each outer portion having an outer end; at least one
frame surface-disrupting element at each outer end; and the central
portion defining a plane and the frame surface-disrupting element
pointing towards the plane; a second member positioned generally
beneath the PV assembly and supported by the support; an elongated
connection member securing the clip to the second member so that
the frame-disrupting element can be forced against the electrically
conductive frame thereby electrically connecting the frame to the
clip; the central portion comprising a hole and the elongated
connection member comprising a connection element passing through
the hole, the connection element having an upper end, the upper end
located completely within the access region and below the upper
surface; and means for preventing the clip from tipping away from
the frame as the clip is biased against the frame by the elongated
connection member.
27. The PV installation according to claim 25 further comprising a
plurality of the frame surface-disrupting elements at each outer
end.
Description
CROSS-REFERENCE TO OTHER APPLICATIONS
[0001] This application claims the benefit of provisional patent
application No. 60/780,819 filed on 9 Mar. 2006, attorney docket
number PWRL 1044-1 and provisional patent application No.
60/821,869 filed on 9 Aug. 2006, attorney docket number PWRL
1045-1, the disclosures of which are incorporated by reference.
STATE SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with State of California support
under California Commission Agreement Number 500-04-022. The Energy
Commission has certain rights to this invention.
BACKGROUND OF THE INVENTION
[0003] This invention generally relates to the mounting of framed
photovoltaic (PV) modules atop roofs and other support structures,
where positive mechanical securement of the modules to the
supporting base or structure is desirable and electrical grounding
of accessible metal components, such as the PV module frame and
ancillary mounting components, is required. Known combined
mounting/grounding devices require a special flange on the outside
of the photovoltaic module frame and a specially designed clip or
other attachment device. Therefore, conventional combined
mounting/grounding devices are limited to use with specific module
frame geometries.
BRIEF SUMMARY OF THE INVENTION
[0004] A first example of an electrically conductive
mounting/grounding clip, for use with PV assemblies of the type
having electrically conductive frames separated by gaps, comprises
an electrically conductive body having a central portion and first
and second spaced-apart arms extending generally perpendicular to
the central portion. Each arm has an outer portion, each outer
portion having first and second outer ends. The clip also has a
frame surface-disrupting element at each outer end. The central
portion defines a plane. The frame surface-disrupting elements
point towards the plane. In some examples the frame
surface-disrupting elements comprise frame-surface-penetrating
teeth. In some examples each arm extends from the central portion
at an acute angle to the plane, such as 80-88.degree..
[0005] A second example of an electrically conductive
mounting/grounding clip, for use with an array of PV assemblies of
the type having electrically conductive frames separated by gaps,
includes an electrically conductive body. The body comprises a
central portion and first and second spaced-apart, generally
T-shaped arms extending from the central portion. Each arm extends
from the central portion at an acute angle to the plane. Each arm
has an outer portion, each outer portion having first and second
outer ends. A plurality of frame surface-disrupting elements are at
each outer end. The frame surface-disrupting elements of each arm
are oriented in a direction generally parallel to a line connecting
the outer ends of said arm. The central portion defines a plane and
the frame surface-disrupting elements point towards the plane.
[0006] An example of an electrically conductive mounting/grounding
clip assembly, for use with an array of PV assemblies of the type
having electrically conductive frames separated by gaps, includes
an electrically conductive clip and a second member. The clip
includes a central portion and first and second spaced-apart arms
extending generally perpendicular to the central portion. Each arm
has an outer portion and each outer portion has first and second
outer ends. A frame surface-disrupting element is it each outer
end. The central portion defines a plane and the frame
surface-disrupting elements point towards the plane. The clip
assembly also includes means for (1) biasing the frame
surface-disrupting elements of the clip against electrically
conductive frames of adjacent PV assemblies thereby electrically
connecting the frames to one another through the clip, and (2)
securing the clip to the second member.
[0007] An example of a PV installation includes a support, first
and second PV assemblies and an electrically conductive
mounting/grounding clip assembly for use with the first and second
PV assemblies. The first and second PV assemblies are of the type
having electrically conductive frames separated by a gap, the
frames each having an upper surface. The clip assembly comprises an
electrically conductive clip. The clip includes a central portion
and first and second spaced-apart, generally T-shaped arms
extending generally perpendicular to the central portion. The
central portion and arms define an access region accessible from
above. Each arm has an outer portion, each outer portion having
first and second outer ends. At least one frame surface-disrupting
element is at each outer end. The central portion defines a plane.
The clip assembly also includes a second member, positioned
generally beneath the first and second PV assemblies and supported
by the support, and an elongated connection member. The elongated
connection member secures the clip to the second member and is
extendable within the gap between the electrically conductive
frames so that the frame-disrupting element can be forced against
the electrically conductive frames thereby electrically connecting
the frames to one another through the clip. The central portion
comprises a hole and the elongated connection member comprises a
connection element passing through the hole. The connection element
has an upper end located completely within the access region and
below the upper surface. In some examples the frame comprises an
electrically non-conductive surface and the frame
surface-disrupting portion comprises surface-penetrating teeth. In
some examples the clip assembly further comprises means for
preventing the clip from tipping away from the frame as the clip is
biased against the frame by the elongated connection member. In
some examples the connection element may include a threaded member,
such as a bolt or a stud.
[0008] A third example of an electrically conductive
mounting/grounding clip, for use with a PV assembly of the type
having an electrically conductive frame, comprises an electrically
conductive body. The body has a central portion and first and
second spaced-apart arms extending generally perpendicular to the
central portion. Each arm has an outer portion with each outer
portion having an outer end. A plurality of frame
surface-disrupting elements are at each outer end. The central
portion defines a plane with the frame surface-disrupting elements
pointing towards the plane. In some examples each arm extends from
the central portion at an acute angle to the plane.
[0009] A second example of an electrically conductive
mounting/grounding clip assembly, for use with a PV assembly of the
type having electrically conductive frame, includes an electrically
conductive clip and a second member. The clip comprises a central
portion and first and second spaced-apart arms extending from the
central portion. Each arm has an outer portion with each outer
portion having an outer end. A frame surface-disrupting element is
it each outer end. The central portion defines a plane and the
frame surface-disrupting elements point towards the plane. The clip
assembly also includes means for (1) biasing the frame
surface-disrupting elements of the clip against the electrically
conductive frame of an adjacent PV assembly thereby electrically
connecting the frame to the clip, and (2) securing the clip to the
second member. The clip assembly further includes means for
preventing the clip from tipping away from the frame as the clip is
biased against the frame by the biasing and securing means.
[0010] A second example of a PV installation comprises a support, a
PV assembly and an electrically conductive mounting/grounding clip
assembly for use with the PV assembly. The PV assembly is of the
type having an electrically conductive frame, the frame having an
upper surface. The clip assembly comprises an electrically
conductive clip. The clip comprises a central portion and first and
second spaced-apart arms extending generally perpendicular to the
central portion. The central portion and arms define an access
region accessible from above. Each arm has an outer portion with
each outer portion having an outer end. At least one frame
surface-disrupting element is at each outer end. The central
portion defines a plane. The frame surface-disrupting element
points towards the plane. The clip assembly also includes a second
member positioned generally beneath the PV assembly and supported
by the support. The clip assembly further includes an elongated
connection member securing the clip to the second member so that
the frame-disrupting element can be forced against the electrically
conductive frame thereby electrically connecting the frame to the
clip. The central portion has a hole and the elongated connection
member comprises a connection element passing through the hole. The
connection element has an upper end located completely within the
access region and below the upper surface. The clip assembly
further includes means for preventing the clip from tipping away
from the frame as the clip is biased against the frame by the
elongated connection member.
[0011] Various advantages, discussed below, accrue through the use
of different examples of the invention. The clip assemblies can
provide both a mounting and electrical grounding function. This
saves considerable material and labor costs as compared to the
conventional approach of running a grounding wire between all PV
modules. The clips are can also be less expensive than typical
tinned copper grounding lugs. The clips can be easily secured to
the modules from above, unlike approaches which require the use of
mounting and grounding holes in the module frame; such holes have
limited accessibility, especially after installation. This reduces
installation and maintenance costs. The clip assembly can be module
neutral; that is, it can be used on any framed PV module in which
at least portions of the frame are electrically conductive for
grounding the PV module. Examples of the invention also do not
require any special construction of the module frame, such as
external flanges specific to a particular module manufacturer. The
geometry of the clip assembly can comprise a direct connection for
grounding as required by Underwriters Laboratories (UL) as opposed
to some other approaches, where the grounding points are not
directly connected to the module frame by the mounting bolt or
stud. Some examples of the clip assembly are amenable to use as a
grounding device independently from its function as a mounting
device, if desired.
[0012] Other features, aspects and advantages of the present
invention can be seen on review of the figures, the detailed
description, and the claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exploded isometric view of a clip assembly;
[0014] FIG. 1A is an enlarged partial side view of the clip of FIG.
1;
[0015] FIG. 2 is an assembled isometric view of the clip assembly
of FIG. 1;
[0016] FIG. 3 is an enlarged cross-sectional view of the clip
assembly of FIG. 2 shown secured to adjacent PV assemblies;
[0017] FIG. 4 is a simplified overall view of two adjacent PV
assemblies secured to one another using the clip assembly FIGS.
1-3;
[0018] FIGS. 5-8 illustrate different types of clip assemblies used
with different types of support structures;
[0019] FIG. 9 is an overall view of a peripheral clip assembly;
[0020] FIG. 10 is a cross-sectional view of the clip assembly of
FIG. 9;
[0021] FIG. 11 shows a clip assembly of FIGS. 1 and 2 used at the
periphery of a PV array with a spacer;
[0022] FIGS. 12 and 13 are exploded isometric and isometric views
of an internal clip assembly; and
[0023] FIG. 14 is a cross-sectional view showing the clip assembly
of FIG. 13 secured to the internal lip of the frame of a PV
assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The following description will typically be with reference
to specific structural embodiments and methods. It is to be
understood that there is no intention to limit the invention to the
specifically disclosed embodiments and methods but that the
invention may be practiced using other features, elements, methods
and embodiments. Preferred embodiments are described to illustrate
the present invention, not to limit its scope, which is defined by
the claims. Those of ordinary skill in the art will recognize a
variety of equivalent variations on the description that follows.
Like elements in various embodiments are commonly referred to with
like reference numerals.
[0025] FIG. 1 is an exploded isometric view of one example of a
clip assembly 10 made according to the invention. Assembly 10
includes a clip 12 secured to a second member 14 by a bolt 16.
Second member 14 includes a base 18, typically of extruded aluminum
or some other appropriate material, and a sealant 20 secured to the
lower surface 22 of base 18. Sealant 20 is typically in the form of
a butyl tape about 3 mm thick. Base 18 has a pair of raised
portions 24 defining a gap 26 therebetween. Gap 26 extends down to
a central region 28 of base 18, central region 28 having a number
of threaded holes 30 formed therein for receipt of bolt 16. Base 18
also has a pair of flanges 32 having a number of mounting holes 34
used to secure second member 14 to a mounting surface, such as a
roof. Bolt 16 passes through a central opening 36 in clip 12,
through a hole 38 formed in a spacer 40, through gap 26, and into a
threaded hole 30. Other types and configurations for base 18, such
as that shown in provisional patent application No. 60/821,869, may
also be used.
[0026] FIG. 2 shows clip assembly 10 in an assembled form while
FIG. 3 illustrates clip assembly 10 of FIG. 2 securing adjacent PV
assemblies to second member 14. FIG. 4 is a simplified overall view
illustrating two clip assemblies 10 engaging adjacent PV assemblies
50 in the gap 58 between the PV assemblies. Clip assemblies 10 are
commonly referred to as interior clip assemblies when used between
adjacent PV assemblies.
[0027] Clip 12 is a generally U-shaped structure having a central
portion 42, through which central opening 36 is formed, and a pair
of upstanding arms 44. Arms 44 and central portion 42 define an
access region 45. Access region 45 is accessible from above to
provide clear access to bolt 16 thus facilitating the use of clip
assembly 10. Arms 44 include extensions 46 having downwardly
extending teeth 48. As shown in FIG. 3, clip assembly 10 is used
with PV assemblies 50 of the type having electrically conductive
frames 52 surrounding PV panels 54. As can be seen in FIGS. 2 and
3, the head of bolt 16 is located completely within access region
45 and is located below the top surface of frame 52 of PV assembly
50. In addition, the generally T-shaped configuration of arms 44
with downwardly facing teeth 48 provide for a low profile
structure. This low profile structure creates a cleaner, less
cluttered appearance and also minimizes shading of PV panel 54.
[0028] Frames 52 have an upper, circumferentially extending edge 56
which are engaged by teeth 48 of clip 12. Frame 52 is typically
anodized aluminum and thus has a non-conductive outer surface.
Frame 52 may also have other types of non-conductive outer
surfaces, such as a painted outer surface. To ensure good
electrical contact between clip 12 and frame 52, teeth 48 act as
surface-disrupting elements. The serrated teeth or other structure
cuts through any nonconductive material on frame 52 thereby
creating a positive electrical connection with clip 12, and via
bolt 16, to second member 14. This helps to ensure good grounding
between frames 52 of adjacent PV assemblies 50 through clip 12.
Other surface-disrupting methods could also be used, such as
causing clip 12 to slide against and score a portion of frame 52 or
through the use of other types of surface-disrupting structures or
procedures.
[0029] In the example of FIGS. 1-3, three teeth 48 are used at each
extension 46 of arms 44. The use of a number of points 44 at each
extension 46 allows some adjustment in the position of clip 12
relative to frame 52, thus facilitating installation. Teeth 48 are
oriented to be generally parallel to a line connecting extensions
46 of each arm 44 and thus generally perpendicular to the adjacent
frame 52.
[0030] Arms 44 are preferably not perpendicular to central portion
42. In the disclosed example, arms 44 extend inwardly over central
portion 42 to define an included angle 53, see FIG. 1A. Included
angle 53 is an acute angle and typically ranges from 80-88.degree.,
and is about 83.degree. in the disclosed example. This helps to
strengthen clip 12 because arms 44 will tend to straighten out
under load. Another advantage with the angulation of arms 44 is
that doing so results in more of a point contact by teeth 48 with
frame 52. This can be for two primary reasons. The first reason is
that teeth 48, for practical purposes, do not narrow down to a true
point but rather to a line or edge, the length of which is as long
as clip 12 is thick. Therefore, by angling arms 44, the ends of
teeth 48 first engage frame 52 to provide more of a point contact
than a line contact. The second reason is based upon the fact that
manufacturing constraints limit how sharp of an edge teeth 48 will
exhibit. In some examples, teeth 48 will exhibit a rounded edge so
that if arms 44 were perpendicular to central portion 42, teeth 48
would provide a generally cylindrical surface against frame 52.
[0031] Clip 12 also secures frame 52 to second member 14 by
capturing the frame between arms 44 of clip 12 and raised portions
24 of base 18. Spacer 40, as suggested in FIG. 3, helps to ensure
adjacent PV assemblies 50 are located in a proper distance from one
another. Spacer 40 is typically made of rubber or some other
material including, for example, metal or cardboard, sized to be
larger than the width of central portion 42, illustrated in FIG. 3.
The size of spacer 40 is chosen so that when PV assemblies 50
expand during hot weather, or otherwise, PV assemblies 50 have room
to expand before contacting clip 12. This helps to prevent damage
to PV panels 54, which could occur if PV assemblies 50 were to
press directly against clip 12 during such thermal expansion. The
use of spacer 40 simplifies installation and by eliminating the
need to use a special tool to ensure proper spacing of PV
assemblies during installation. Although the primary grounding
created by clip 12 is from frame 52 of one PV assembly 50 to frame
52 of an adjacent PV assembly, clip assembly 10 can also be used to
provide grounding between PV assembly frames 52 and second member
14.
[0032] Clip assembly 10 provides a low profile mounting/grounding
clip assembly usable with a wide variety of PV assemblies of the
type having an electrically conductive circumferential frame having
an exposed upper peripheral surface.
[0033] FIG. 5 illustrates a clip assembly 62 that uses a clip 64
similar to clip 12 but turned upside down with teeth 48 facing the
opposite direction so that they also pointed downwardly to engage
frame 52 of PV assemblies 50. In addition, instead of using a
central bolt 16, clip assembly 62 has a pair of L-shaped legs 66
extending downwardly from the arms 68 of clip 64. Second member 70
in this example has an upwardly extending stud 72 passing through a
hole, not shown, formed in the bent end 74 of each leg 66 with a
nut 76 securing leg 66 to second member 70.
[0034] FIGS. 6 and 7 disclose further alternative embodiments
similar to the embodiment of FIGS. 1-4, with a stud-type mount in
FIG. 6 including a stud 78 and a nut 80 and a bolt type mount in
FIG. 7, and a different type of second member 82 supporting PV
assemblies 50. The second members supporting PV assemblies 50 in
FIGS. 5-7 are used to support sloped PV assemblies. This type of
structure is shown in more detail in U.S. patent application Ser.
No. 11/616,575, filed 27 Dec. 2006, entitled Supported PV Module
Assembly, attorney docket number PWRL 1041-2, the disclosure of
which is incorporated by reference.
[0035] FIG. 8 shows a still further embodiment in which clip
assembly 84 includes a clip 64 connected to a pair of wind
deflectors 86. Wind deflectors 86 may be of the type shown in the
above referenced U.S. patent application Ser. No. 11/616,575. Clip
assembly 84 also includes an L-shaped leg, not shown but similar to
L-shaped leg 66 of FIG. 5, to provide an electrical ground
connection and a hold down or support function for PV assemblies
50. A clip assembly can also be constructed to provide securement
point(s) for other photovoltaic array components, such as a ballast
pan, a visual shield, a fire shield, a wire tray or wire securement
device, or a structural member. The securement points(s) may
consist of a mounting hole, a threaded stud, or a snap fit device.
A clip assembly can also provide an attachment point for a
conventional grounding lug or grounding wire. A particular
securement point may also act as both a structural point and
grounding point. Unlike clip assembly 10, clip assembly 62, 84 of
FIGS. 5 and 8 are most useful for use with PV assemblies 50 having
frames 52 of a chosen height.
[0036] FIGS. 9 and 10 illustrate what is sometimes called a
peripheral clip assembly 88. Unlike clip assemblies 10, 62 and 84,
a peripheral clip assembly 88 is used to securely mount PV assembly
50 and may be used to ground frame 52 to a support member. Similar
types of installations are shown in U.S. Pat. Nos. 6,058,930 and
6,722,357, attorney docket numbers PWRL 1026-1 and 1027-1, the
disclosures of which are incorporated by reference. In this
embodiment perimeter clip 90 is secured to second member 92 using a
bolt 16, an optional washer 94, and a standoff 96. The length of
standoff 96 is determined by the height of frame 52. Standoff 96
helps to prevent perimeter clip 90 from tipping away from frame 52
when bolt 16 is tightened. Other types of spacers may also be used
for this purpose. Bolt 16 grounds frame 52 to second member 92,
which in this embodiment is a laterally-extending support mounted
to a torque tube 98 of a tilted, tracking solar collector assembly.
In this case frames 52 of a row of PV assemblies 50 are grounded to
one another through second member 92 and, optionally, to other rows
of PV assemblies through torque tube 98 and other second members
92.
[0037] Clip assembly 10 of FIGS. 1 and 2 can be used at the
periphery by using, for example, a spacer 100 located between the
otherwise unused extensions 46 of clip 12, see FIG. 11, and the
second member 14. Spacer 100 has a periphery 102 configured to
accommodate frames 52 having different heights. Other types of
variable-height of spacers, including threaded, telescoping spacers
and spacers consisting of stacks of individual spacer elements, can
also be used.
[0038] FIGS. 12-14 illustrate an internal clip assembly 106
designed as a modification of clip assembly 10 of FIGS. 1 and 2.
Clip assembly 106 includes a clip 108 and pieces of electrically
insulating adhesive-backed tape 110, 112. Tape 110 is secured to
raised portions 24 of base 18 to cover the end of upper surface 114
opposite clip 108. Tape 112 is adhered to clip 108 as shown in
FIGS. 12 and 13 to lie above gap 26. Bolt 16 is tightened onto base
18 and then PV assembly 50 is secured to clip assembly 106 by
sliding an internal lip 116 of frame 52 between clip 108 and base
18 engaging insulating tape 110, 112. In this example internal clip
assembly 106 acts to secure PV assembly 50 in place but does not
provide a grounding function. In other examples internal clip
assembly 106 could be configured to provide a grounding function as
well as a mounting function by, for example, causing a spike to
pierce the surface of lip 116 when the lip is inserted between clip
108 and base 18. Tape 110, 112 helps to ensure the snug engagement
of lip 116 between clip 108 and base 18 and also helps to reduce
marring of the surface of lip 116. Although tape 110, 112 is in
this example electrically insulating, it need not be.
[0039] The above-described embodiments have a clip assembly
supported by a support. The support is typically a commercial or
residential roof or support frame member for a solar energy
tracking system. The support can also include trellises, carports,
shade structures, and so forth. The clip assembly can also be
supported directly on the ground.
[0040] The clip assembly is preferably designed to withstand uplift
and lateral loads as appropriate for the application. The clip
materials are chosen for required strength, corrosion resistance,
and aesthetics.
[0041] During installation the mounting bolt may be torqued such
that the threaded member and the clip are pre-loaded above the
maximum code wind load plus an appropriate safety factor. This
ensures a secure mechanical and electrical connection in all field
conditions and excludes moisture from the ground bond area at teeth
48 by creating a high pressure connection zone around each
point.
[0042] The use of threaded connections has been emphasized.
However, other types of connections, such as a ratchet-type of
connections and connections using spring fingers, may also be
used.
[0043] The above descriptions may have used terms such as above,
below, top, bottom, over, under, et cetera. These terms are used to
aid understanding of the invention are not used in a limiting
sense.
[0044] While the present invention is disclosed by reference to the
preferred embodiments and examples detailed above, it is to be
understood that these examples are intended in an illustrative
rather than in a limiting sense. It is contemplated that
modifications and combinations will occur to those skilled in the
art, which modifications and combinations will be within the spirit
of the invention and the scope of the following claims. Any and all
patents, patent applications and printed publications referred to
above are incorporated by reference.
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